Four winns 318 VISTA Owner's Manual page 122

NOTICE
Most air conditioners utilize surface water as
the cooling medium. Prior to using the air
conditioning, the boat must be in the water and
the seacock to the air conditioning water intake
must be in the open position. The air
conditioning seacock for water intake is below
the aft cabin access panel. Operating air
conditioners without proper cooling water will
cause damage to the air conditioning system.
Air.conditioners.utilized.in.Four.Winns
are.equipped.with.reverse.cycle.heat..Thus,.some.
heat.effect.can.be.derived.from.the.unit..It.must.be.
noted.that.the.amount.of.heat.that.can.be.obtained..
is.limited.by.the.temperature.of.the.raw.cooling.water.
pumped.through.the.system..When.the.water.tem-
perature.drops.to.40.degrees.Fahrenheit,.the.output..
is.about.50%.of.the.maximum..At.36.degrees.Fahren-
heit,.the.output.is.very.low..
NOTICE
During cold conditions, an alternate or supple-
mental heating system should be used.
Clean.the.sea.water.strainer.often..Also,.clean.the.
return air filter screens, located behind the louvered
doors.and.grills,.at.least.once.a.month.
To.winterize,.refer.to.the.manufacturer's.literature.
included.in.the.owner's.packet.
Interior Equipment - Section L
.Vista .models.
® ®
Owner's Manual Page